Strike-induced chemosensory searching by the anguid lizard Elgaria coerulea

Abstract

AbstractStrike-induced chemosensory searching (SICS), including a post-strike elevation in tongue-flick rate (PETF) and searching movements following experimental removal of prey from the predator's mouth, is demonstrated to occur in an anguid lizard, Elgaria coerulea. This finding confirms predictions based on the previously established widespread occurrence of SICS in scleroglossan (especially autarchoglossan) lizard families and on a strong association between SICS and active foraging. Reasons why SICS should be favored by natural selection in active foragers are discussed, but the presence of SICS in anguids is attributed to phylogenetic inertia rather than adaptation. SICS was statistically significant only during the first two minutes in E. coerulea. Its limited duration in an anguid and much greater duration in helodermatids, varanids, and snakes suggest that prolonged SICS may have had a single origin in the common ancestor of Varanoidea or, much less likely, of (Varanoidea + Xenosauridae). Uncertainties about origins due to missing data on certain taxa and to unresolved phylogenetic relationships within Seleroglossa are discussed.